ess-mode [elpa: 25.1.0]; ESS doesn't respect R_HISTFILE and R_HISTSIZE

[jun8git]

I’ve noticed that ESS requires setting comint-input-ring-size,
ess-history-file, and ess-history-directory for managing R command
history. However, I believe ESS should also respect R’s native
environment variables, R_HISTFILE and R_HISTSIZE, for consistency with
R’s default behavior.

I came across a related discussion from 2009
(https://stat.ethz.ch/pipermail/ess-help/2009-September/005555.html). The
R documentation
(https://search.r-project.org/R/refmans/utils/html/savehistory.html)
confirms that these variables control history handling in R.

Would it be possible to align ESS with R’s built-in history
management? This could either be treated as a bug fix (if
unintentional) or a feature request (if a deliberate design choice).

Thank you for your time and for maintaining ESS. It’s an invaluable
tool for GNU R users!

Emacs : GNU Emacs 30.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.43, cairo version 1.18.2)
Package: ess-mode [elpa: 25.1.0]

[mmaechler]

Yes, it would be possible and a good idea, I think.
Honestly it may not have the greatest impact in the world, as all this is probably not so much used (consciously).
Note that ESS predates R and its history handling was originally done for S, then S-PLUS ... so the ESS core team just kept maintaining was already there, when R became the main system for which ESS was used.. -> "patches welcome", i.e., we are fine with a pull request notably if you try to keep it as back compatible as possible ...